The invention relates to a disc-shaped retaining device for bushings of a rotary tablet press, in particular a die table for die bushings of a rotary tablet press. Segmented and unsegmented die tables are known. A segmented die table, i.e. a die table for a rotary tablet press constructed of multiple die segments, especially annular die segments, is, for example, known from DE 101 59 114 B4, the entire contents of which is incorporated herein by reference. In the case of said die table, the upper and lower punches directly interact with boreholes of the die segments. Sometimes it is desired to place sleeve-like die bushings in the die holes, within which pulverised material is pressed into tablets between the upper and lower punches during operation. Such die bushings are fixed, for example, through bonding, shrinking, impression or screwing. When they are screwed, generally radial attachment screws are applied to the die bushings.
The known types of fastening for the die bushings do not always, however, reliably sustain the great forces that occur during operation. The latter in particular does apply to non-form-fit connections. With screwed bushings, for example, due to exposed screw threads, gaps and hollows, difficulties occur with regard to cleaning pulverised material which inevitably occurs during operation. Bonded bushings require an adhesive, which—in particular when manufacturing tablets for the pharmaceuticals industry—need to fulfil high approval requirements, for example those of the U.S. Food and Drug Administration (FDA). Furthermore, an increased space requirement arises through the known types of fastening, which leads to restrictions in regard to the number of die bushings to be accommodated and the size of the tablet formats to be manufactured. The known die tables or die segments can, moreover, depending upon the type of fastening, only be used for the die bushings on one side.
Taking as a starting point the prior art explained, the task of the invention is to provide a disc-shaped retaining device of the kind mentioned at the beginning, in which bushings can be fastened in a simple, compact and secure manner.
The invention resolves this task through the subject of claim 1. Advantageous designs can be found in the dependent claims, the description and the figures.
The invention resolves the task by means of a disc-shaped retaining device for bushings of a rotary tablet press, characterised in that the disc-shaped retaining device comprises two disc halves that are connected with one another, each of which shows multiple holes, and which align with one another if the disc halves are connected with one another and thus form mounting holes into which one respective bushing is placed, wherein the bushings between the disc halves that are connected with one another are designed in a form-fit manner. The disc-shaped retaining device may in particular be a die table. Accordingly, the bushings may in particular be die bushings.